In recent years as smartphones and wearable devices have become popular, there have been proposed many services that are provided based on the position to which they move (augmented reality, navigation, communication, maintenance, sales support applications, or the like) (e.g. Non-patent document 1).
There are various positioning methods for locating an object on the move. GNSS (Global Navigation Satellite System) is a method in which navigation signals transmitted from satellites are received to determine the current position and direction. QZSS (Quasi-Zenith Satellite System), a method that uses satellites that orbit almost directly over Japan, is a technology that complements GPS, which is a kind of GNSS.
In a Wi-Fi (registered trademark) method, a radio wave transmitted from a Wi-Fi base station is received to estimate the current position from the radio field intensity or the SSID. iBeacon (registered trademark) is a communication function using short-range wireless communications developed by Apple, and conforms to Bluetooth (registered trademark) 4.0LE. In a sound wave signal method, a transmitter (speaker) that generates a sound wave or ultrasonic including an ID is installed, a receiver (microphone) attached to the device receives it, and the position is detected from the ID (e.g. Patent document 1). NFC (Near Field Communication (also called RFID)) is a near field wireless communication technology known as FeliCa (registered trademark), MIFARE, or the like, and can identify the subject by bringing the device close to the system. These methods involve determining in advance the positions corresponding to positioning signals (e.g. the positions of devices that transmit positioning signals), receiving a single or plurality of positioning signals, and estimating the current position from information on the position corresponding to each positioning signal.
PDR (Pedestrian Dead Reckoning) is a method that integrates a very small change detected by sensors of the device to estimate distance and direction, and can estimate the current position using the relative travel distance and direction from the previous position. It can therefore be used in combination with the above-described various methods that involve receiving positioning signals.